from fastapi import FastAPI, HTTPException, Request, status
from fastapi.encoders import jsonable_encoder
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from fastapi.responses import PlainTextResponse
from pydantic import BaseModel
from starlette.exceptions import HTTPException as StarletteHTTPException


app = FastAPI()


'''
1.2 使用 HTTPException
'''

items = {"yinyu": "The Foo Wrestlers"}

@app.get("/items/{item_id}")
async def read_item(item_id: int):
    if item_id not in items:
        raise HTTPException(status_code=404, detail="Item not found")#触发 HTTPException 时，可以用参数 detail 传递任何能转换为 JSON 的值，不仅限于 str。还支持传递 dict、list 等数据结构。
    return {"item": items[item_id]}



'''
2.1 自定义响应头
'''
@app.get("/items-header/{item_id}")
async def read_item_header(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "There goes my error"} #添加自定义响应头
        )
    return {"item": items[item_id]}



'''
2.2 自定义异常处理器
'''
class SelfDefinedException(Exception):
    def __init__(self, name: str):
        self.name = name

@app.exception_handler(SelfDefinedException)
async def defined_exception_handler(request: Request, exc: SelfDefinedException):
    return JSONResponse(
        status_code=418,
        content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
    )

@app.get("/self_defined/{name}")
async def read_defined(name: str):
    if name == "yolo":
        raise SelfDefinedException(name=name)
    return {"unicorn_name": name}


'''
2.3 覆盖默认异常处理器
'''
'''覆盖请求验证异常'''
@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request, exc):
    return PlainTextResponse("RequestValidation:"+str(exc), status_code=400)

@app.get("/items2/{item_id}")
async def read_item(item_id: int):
    if item_id == 3:
        raise HTTPException(status_code=418, detail="Nope! I don't like 3.")
    return {"item_id": item_id}

'''覆盖 HTTPException 错误处理器'''
@app.exception_handler(StarletteHTTPException)
async def http_exception_handler(request, exc):
    return PlainTextResponse(str(exc.detail), status_code=exc.status_code)

@app.get("/items3/{item_id}")
async def read_item(item_id: int):
    if item_id == 3:
        raise HTTPException(status_code=418, detail="Nope! I don't like 3.")
    return {"item_id": item_id}

''' 使用 RequestValidationError 的请求体'''
@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request: Request, exc: RequestValidationError):
    return JSONResponse(
        status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
        content=jsonable_encoder({"detail": exc.errors(), "body": exc.body}),
    )

class Item(BaseModel):
    title: str
    size: int

@app.post("/items4/")
async def create_item(item: Item):
    return item





if __name__ == '__main__':
    import uvicorn
    uvicorn.run(app, host="127.0.0.1", port=8000)